Macbook Keyboard problems

Hey!
so, I have an issue with my old mac book's keyboard and trackpad, it would be pretty awesome if someone on here knows *** to fix it. It's an early 2008 13" Mac Book (the plastic ones) I believe 160Gb HD, 2.1GHz core 2 duo. So here's the story:

My wife spilled soup on the keyboard and the keyboard and track pad stopped working. So I found the correct replacement for my computer and installed it. It works fine for about 20 minutes after boot up and then it just stops working again. The computer wasn't damaged and it works fine with an external mouse and keyboard but the built in one keeps either failing or stops being detected by the computer. Has anyone experienced something like this before? I've taken it out and reinstalled it multiple times with the same or similar results. It will either not work at all, or work for 20 minutes and then quit.

Any tips or tricks you guys have would be amazing. I'm trying to get it working again so I can sell it (fingers crossed)

Thanks in advance for any responses.

Chances are the soup not only destroyed the keyboard and trackpad, but also leaked down through to the logic board where the keyboard connector is attached. Did you clean the logic board to make sure no residue from the soup remains on it?

yeah, I wiped everything down with some alcohol and let it dry over night. I checked and double checked the plug and the receptor on the keyboard but they are both clean. It seems if I take the battery out and leave the power off for some time the key board is more likely to work when I turn the system back on, but it will always become unresponsive after a few minutes of used. Still have no idea whats causing it...
Thanks for the comment though

Solution: Have your wife buy a new one